FT's FREE POWERMETER

[ft_critical]

Just like the iBike, but without any messy installation/calibration comes FT’s free powermeter:

Components:
1. The Watch: Stop Watch
2. The Toaster: http://www.bikeroutetoaster.com/Course.aspx
3. The Slope: http://sportech.online.fr/sptc_idx.php?pge=spen_esy.html
4. The Scales: your bathroom scales
5. The BOM: http://www.bom.gov.au/nsw/observations/sydney.shtml
6. The Power: http://sportech.online.fr/sptc_idx.php?pge=spen_esy.html
Operation:
1. Get on your bathroom scales with your bike in your kit with a water bottle --> weight.
2. Get the temp and wind speed/direction from the BOM.
3. Map a climb or more on your route using the Toaster, noting the elevation gain and distance.
4. Calc the Slope.
5. Time your ascents.
6. Punch all this information into the Power and bang instant power measurement.
7. You can refine it by determining your drag, tyre pressure and rolling resistance.

I think this works for climbs and would be a decent benchmark for performance testing. Enjoy.

So Philip and I did Boundary riders this morn and here is our power:
Roseville Bridge Hill and Parrawi Hill in Mosman 400watts on the nose for each. That is basically ascending a 4.5 grade at 25.5kmh. Philip was a bike length to the good on each and weighs less so the numbers will be slightly different.

[philip]

Haha.. if I put in my (very rough) figures (me 75kg, bike weight 10kg) that gives me 390W and Power/Weight: 5.21 W/kg.. which from what I've read in other threads is not a bad figure? Also from the graph it tells me I'm using 67.9% of my power to overcome gravity; gravity is a bitch!

If you value your time (and accuracy) I think it might be cheaper to get a real power meter

[sogood]

Issue is, power numbers are only meaningful if associated with a time period. Best power over 6mins means very different to best power over 20mins.

[philip]

Parriwi is 3 mins, Roseville I think slightly longer.. though I seem to be incredibly bad at estimating time when I'm pushing hard!

[sogood]

...though I seem to be incredibly bad at estimating time when I'm pushing hard!

Aren't we all. Time seemed to either stop or jump when pushing hard. Either way, it becomes non-linear. Maybe the corresponding velocity has something to do with it.

[ft_critical]

Parriwi is 3 mins, Roseville I think slightly longer.. though I seem to be incredibly bad at estimating time when I'm pushing hard!

Timing points and dist for Roseville were for a 4min18sec effort. It makes me laugh. I remember reading the stats on Kurt on the tour, well on the tour riders in general but more the domestiques. They were making 20min efforts at 400watts - most days. That is like 4 times what I can do.

[MichaelB]

I won't report what my power is up Corkscrew Rd here in Adelaide

Using a different calculator from Hillclimbr.com gives a figure that is 6.2% lower (318w vs 338W from FT's link).

I'd be happy to be able to climb like Kenny van Hummel ....

[Alex Simmons/RST]

Here's an item on climbing and the impact of wind on power estimates:
Ascension rates and power to weight ratios

[ft_critical]

Using a different calculator from Hillclimbr.com gives a figure that is 6.2% lower (318w vs 338W from FT's link).

Spoil yourself Michael, call it 340watts rounded